Phenylalkanoates



United States Patent 3,259,647 PHENYLALKANOATES Henry E. Hennis, Midland, Mich., assignor to The Dow Chemical Company, Midland, Mich, a corporation of Delaware N 0 Drawing. Filed Sept. 7, 1962, Ser. No. 222,214

3 Claims. (Cl. 260-476) CHz-C H2 wherein n is 1 or 2. Under ordinary conditions the compounds are colorless liquids, slightly soluble in water, readily soluble in acetone, 95 percent ethanol, xylene, and similar organic solvents. The compounds are useful for the control of mites and insects, and have herbicidal and fungicidal properties.

The compounds are prepared by esterifying cyclohexylmethanol with phenylacetic or hydrocinnamic acid, or with an alternative acid source such as phenylacetic or hydrocinnamic acid anhydride, or an ester thereof, other than cyclohexylmethyl; or pheny-lacetyl or hydrocinnamyl halide. Preparation of the present compounds consumes the alcohol and acid, ester, or halide starting material in equimolecular proportions, or anhydride in proportions half equimolecular with alcohol. The employment of such proportions in reaction mixture is efficient. Other amounts may be employed if desired. When employing acid and alcohol, water of reaction is stoichiometrically formed and its formation may be taken as an indication of progress of reaction. It can be removed readily in known procedures as by azeotropic distillation.

In carrying out the reaction to prepare the present compounds, phenylacetic or hydrocinnamic acid or other such acid source as has been mentioned is intimately mixed and stirred together with cyclohexylmethanol, desirably in the presence of an acidic esterification catalyst. The reaction goes forward smoothly at temperatures over a wide range, and is preferably carried out with moderate heating, as, for example, at the temperature of boiling water. Advantageously, the reaction is carried out in an inert liquid reaction medium, such as toluene, xylene, or the like. Preferably such reaction medium should be capable of forming a water azeotrope whereby, in carrying out the reaction under reflux equipped with water separator and at the boiling temperature of the reaction medium, water of reaction is continuously removed as it is formed. Some product is formed immediately upon contacting of the reactants. Upon completion of the esterification reaction, a crude product is present in good yield and may be employed in that form if desired. When it is desired to obtain the product in the absence of such impurities as catalyst and reaction medium, pure product may be separated in known methods, for example, by neutralizing and washing away catalyst and by fractional distillation.

The following examples, without more, will enable those skilled in the art to practice the present invention.

Example 1 Into a 2-liter 3-necked round-bottomed flask equipped with a motor stirrer, thermometer, and azeotropic distillation column was placed 272.3 grams (2 gram moles) of phenylacetic acid, 228 grams (2 gram moles) of cycloice hexylmethanol, 10 grams of p-toluenesulfonic acid as catalyst, together with 500 milliliters of toluene. The resulting reaction mixture was heated with stirring, continuously over a period of between 4 and 6 hours, during which time water of reaction formed and was continuously removed from the reaction mixture by azeotropic distillation with reflux of solvent. At the conclusion of the reaction time, the resulting reaction mixture was allowed to cool and was then poured into 500 grams crushed ice. As a result of these procedures, ice melted and the resulting mixture separated into aqueous and organic phases. The phases were separated, and the organic phase layer washed twice with 500 milliliter portions of aqueous 5 percent sodium bicarbonate solution and thereafter twice with 500 milliliter portions of water. The resulting washed organic solution was thereafter fractionally distilled at gradually increasing temperatures and declining subatmospheric pressures whereby there was obtained a cyclohexylmethyl ester of phenylacetic acid, as a colorless liquid boiling at 112 C. under a pressure of 0.3 millimeter mercury, absolute. The product liquid had a refractive index n/D at 25 C. of 1.5072. Upon the basis of elemental analysis, its purity was calculated to be 99%. The assigned structure is confirmed by infrared analysis.

A spray dispersion was prepared, containing as sole toxicant, the compound of the present example at the rate of 1 pound thereof per hundred gallons of resulting aqueous dispersion. This preparation was applied as a thorough wetting application to all surfaces of the leaves and stems of young bean plants heavily infested with a known population of 2-spotted spider mites. The infested plants were then set aside under conditions favorable for the growth of the mites for 3 days and thereafter examined. It was ascertained that the population of 2-spotted spider mites had been completely killed, no live mites being found to be present. The kill was, statistically, 100%.

In synthetic procedures similar to those indicated, foregoing, there was prepared the cyclohexylmethyl ester of hydrocinnamic acid. The product was prepared in good yield, and was found to be a colorless, oily liquid boiling at 118 C. under a pressure of 0.1 millimeter mercury, absolute. Upon the basis of elemental analysis and confirmatory infrared spectrum data, the structure was confirmed and the product ascertained to be approximately pure. It was found to be soluble to the extent of less than 1% in water; it was readily soluble in acetone, ethanol, xylene, and mixed lower aliphatic hydrocarbon liquids. The compound was tested and found to have distinct fungistatic activity against Phytophthora infestans, the causal organism of late blight of tomatoes.

I claim:

1. Compound of the formula GET-CH2 wherein n represents an integer selected from 1 and 2.

2. Cyclohexylmethyl phenylacetate. 3. Cyclohexylmethyl hydrocinnamate.

References Cited by the Examiner UNITED STATES PATENTS 2,441,183 5/1948 Bludworth et a1. 260468 LORRAINE A. WEINBERGER, Primary Examiner.

LEON ZITVER, Examiner.

R. E. MASSA, T. L. GALLOWAY, Assistant Examiners.

3 ,250,647 Patented July 5, 1966. 

1. COMPOUND OF THE FORMULA 